I was reading about reducing wine and came across a claim that alcohol itself has no flavor.

But, what about the alcohol? Ethanol, or ethyl alcohol—the byproduct of yeast fermentation—has no flavor of its own. By that I mean it does not trigger any receptors in the tongue or nose. It does have a effect, which results from the alcohol interacting with the cells in the mouth. If you are planning on using a wine in cooking, particularily if it will be reduced or simmered, the alcohol should have no effect on flavor.

However, from my past experience, that's simply not true. Or if it is, where does the bad flavor of strong spirits come from? It's more than just the "burn" of the alcohol, if I mixed everclear with water to where it was around the same strength of wine, it would taste nasty. Why is that?

Er ... part of your quote reads "It does have a effect, which results from the alcohol interacting with the cells in the mouth"
– dmckeeNov 25 '14 at 4:43

Which I construe as the burning sensation because it doesn't interact with taste buds
– MalfistNov 25 '14 at 4:58

Strong spirits are still far away from 100% ethanol. IMO our taste buds are sensitive enough to detect taste in even in remaining 1% of non-ethanol.
– EuphoricNov 25 '14 at 7:28

I may agree that ethanol not necessarily has a "taste" in the sense that it doesn't trigger any of the classical taste buds. The burning sensation does however have an impact on the perception of taste, just as the reaction to capsaicin in chili peppers (which following the same logic would also have to be considered tasteless). In addition, ethanol has a significant smell, also contributing to what we colloquially summarize as "taste".
– Tor-Einar JarnbjoNov 25 '14 at 12:30

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Those of us who have worked our way up the scale to tolerate very strong alcohol (via cask strength whisky of ca 60% alcohol) can report that pure (i.e. 99% pure laboratory ethanol - be careful, though, not all "pure" lab ethanol is safe to drink) tastes very slightly sweet. Probably due to a weak affect on the same receptors as normal sugars.
– matt_blackNov 26 '14 at 22:07

1 Answer
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Alcohol chains are highly volatile and the resulting vapors are detectable by the human olfactory sense as odor. Ethanol is the least detectable, but still registers above chance levels according to the linked study as listed in the abstract which does not require membership/subscription to read, but for ease I will link and quote the abstract:

ABSTRACT We explored in humans concentration-detection functions for the odor of the homologous n-alcohols ethanol, 1-butanol, 1-hexanol, and 1-octanol. These functions serve to establish structure-activity relationships, and reflect the pharmacology of the olfactory sense at the behavioral level. We tested groups of 14 to 17 subjects (half of them females), averaging 31 to 35 years old. An 8-station vapor delivery device (VDD8) presented the stimulus under a three-alternative forced-choice procedure against carbon-filtered air. The VDD8 was built to meet the demands of typical human sniffs in a short-term (<5 s) olfactory detection task, and to accurately control odorant generation, delivery, and stability. Actual stimulus concentration was quantified by gas chromatography before and during testing. The functions obtained were log normally distributed and were accurately modeled by a sigmoid (logistic) function, both at the group and at the individual level. Sensitivity to ethanol was the lowest and to 1-octanol the highest. Functions became steeper with increasing carbon chain length. For all alcohols the concentration detected halfway between chance and perfect detection (threshold) was at the ppb (or nM) level. Females were slightly more sensitive than males. Intersubject variability across participants was between one and two orders of magnitude. The present odor thresholds were lower than many reported in the past but their relative pattern across alcohols paralleled that in our earlier data and in compilation studies. A previously described quantitative structure-activity relationship for odor potency holds promise to model thresholds that, like those obtained here, best reflect the intrinsic sensitivity of human olfaction.